Remus Lupin hadn't smoked before the war; he knew it was bad for him and that he should avoid them.
Then he spent tension-filled nights keeping St. Mungo's out of Death Eater hands. Even the non-smokers lit up in that little room where they waited for the attack they felt was imminent.
They all smoked differently; James would have one just dangling from his lips most of the time, taking a puff every now and again, Peter would light up only if James did. Lily would light hers off of someone else's and Alice would keep one unlit behind her ear. Kingsley would smoke his all the way down to the filter and Sirius smoked in chains, one, and then another less than five minutes later, looking so handsome with his five o'clock shadow, lighting each one with that silver-coloured lighter James had given him.
He finally gave in when he saw the glow of lights head towards the group; fairly certain this would be their last moments on this earth. He asked Sirius for one, placed it into his mouth and then Sirius lit it. It was strong, he had coughed a lot. He was sure that if he lived to see the next day he would not smoke again.
The battle had been difficult; Fenwick had been hit with two stunners to the chest; James, knocked unconscious with one spell or another; and Sirius had been cornered by his 'family' and survived the battle, due in large part to Frank and Gideon's speed in coming to his aid. Remus and most of the rest of the group survived with only a few small injuries. It was a successful night, five death eaters had been killed, three captured.
After the dust cleared and most of the wounds tended, Caradoc Dearborn, a handsome man in his early twenties with dark hair and an almost devilish goatee, offered Remus another cigarette. It was something about the way the man smiled that make Remus take it. He took it of course, but this time he actually enjoyed it. It tasted the way Sirius tasted when they kissed; something he now regretted thinking.
He became addicted during the war; bumming whatever brand he could get, usually Dragon's Breath, which was popular among most of the group. He preferred Royals though, the brand Sirius, and prior to his death, Edgar Bones, smoked.
But then the war ended. James was dead, Lily and Peter too. Sirius had killed them. Smoking was no longer a social activity. None of his war friends spoke to him anymore; probably figuring he needed space to grieve. He would have liked to see them though; all time alone was doing was letting vice rear its head.
He drank, not to excess, but at least one drink a day. He chain smoke; which only made him feel worse because that was what Sirius had done. That was what actually made him want to quit, knowing that was what Sirius did; not his father telling him he smelt horrible when he hugged him, nor anyone telling him to quit; just the reminder that Sirius had done it.
He had tried again and again, throwing away almost full packs of cigarettes, and then regretting it later when he caved in and bought a new one. It wasn't even the nicotine; at least Remus didn't think it was. After all he didn't smoke around people, could go for days without a smoke. He only did it when he was alone, the times he missed Sirius' lips on his, the smoke on the other man's breath the most.
So Remus decided not to be alone. He started going out, taking men home, just to take the edge off his loneliness. They all looked the same; tall, thin, pale skin, dark hair. They took the edge off, but not much more. Most of them would want a second evening with Remus but he'd always say no, not wanting people too close.
But the smoking stopped. He started owling old friends; started to rebuild his life. He enrolled in college, to get his doctorate, or master's degree at least, in English literature. It meant not buying new clothes, and sometime skipping meals, but it kept him busy. He worked odd jobs for friends or family sometimes to make ends meet.
But every time he saw Sirius' name in the Prophet or found an old photo of them together, he'd begin again. Always wishing Sirius had been innocent so that he could taste this on the other man's lips instead of through paper.